Humidostat and like devices



June 11, C. A. OTTC HUIIDOSTAT AND LIKE DEVICES Filed May 2a, 1938 Srmmtor @wzEQLOi/ko attomegs Patented June 11, 1940 UNITED. STATES HUMIDOSTAT AND LIKE DEVICES Carl A. Otto, Milwaukee, Wis., assignor to Johnson Service Company, Milwaukee, Wis., a cor-- poration of Wisconsin Application May 26, 1938, Serial No. 210,215 I 12 Claims.

This invention relates to control devices which automatically respond to variable physical conditions such as humidity, temperature, pressure and the like.

The invention, although it will beherein described as embodied in a humidostat as a typical example, is applicable to humidostats, thermostats, hygrostats, pressure-responsive controllers and the like, by ready substitution of known -elements responsive to corresponding variables.

Patent No. 1,500,260 to Otto et 8.1., July 8, 1924, discloses a progressive thermostat, humidostat or like device of the pneumatic relay type. In operation, this device functions to establish in a branch line, connected to the relay and to a controlled device (such, for example, as a humidifying apparatus or a heater 'valve), a pressure which varies progressively in response to variable throttling by a responsive element of a leak port connected to the relay and a main line leading to the latter. The patent also shows manually operable adjusting means on the instrument for varying the critical point of response (leak port just closed) by changing the relative position of the leak port and its throttling means.

With the well-known insertion type of humidcstat, thermostat or the like, which operates on the above principle and to which type of device the present invention particularly relates, the responsive element extends from the instrument body into a duct or other space and senses the relative humidity of the air inside of the duct, in the case of a humidostat. It frequently happens in maklng installations that the place where the humidostatic element. must be inserted in the duct is not readily accessible. This renders it quite diflicult to mount the humidostat. Oftentimes there is very limited space for the humidostat body, whicli includes the relay, or it is difficult to bring the main line and branch pipes to the point where the humidostat is mounted. Furthermore, under such conditions, it is also difllcult to readjust the setting of the humidostat because the manually operable adjusting means thereon cannot be reached easily. Therefore, readjustment is often neglected.

It is the particular purpose of the present invention to overcome the above difllculties. This is accomplished by separating the humidostat body from the assembly comprising the sensitive humidostatic element, the leak port and the throttling means, and providing extended operating connections, between this assembly and the humidostat body, for the leak port and the setting adjusting means. Thus the humidostatic element may be inserted into the duct or other space at the point required, regardless of its accessibility, while the humidostat body, with means for readjusting the instrument setting, is located at a convenient place where it may be easily reached, as for example. by mounting on a central switchboard. An important feature is that the construction and arrangement of the. extended operating connections between the responsive element assembly and the humidostat body are such as to insure efiicient operation of the instrument and accurate manual readjustment thereof even though the responsive element and the instrument body be located at a considerable distance from each other.

Another feature is that the operating connections above referred to are compactly and neatly arranged and fully protected from possible damage which might interfere with proper functioning of the instrument. A further feature is the provision, in conjunction with setting adjustment indicating means at the humidostat body, of au tomatic means to compensate for lost-motion in the setting adjusting means, so that accurate indication will be given of the setting of the instrument at all times. Other features and advantages will appear hereinafter.

A practical embodiment of the invention will now be described with reference to the accompanying drawing in which:

Figure 1 is a consolidated view of an insertion type humidostat showing, in vertical axial section, the humidostatic element assembly mounted in place on a duct and, in front elevation, the humidostat body with attached relay, air lines and remote manual adjusting means, and also the extended operating connections between the {)eJsponsive element assembly and the humidostat Fig. 21s a section on line 2-2 of Fig. 1 showing certain details of the remote adjusting means and the indicating means;

Fig. 3 is a fragmentary bottom view of Fig. 2; and

Fig.4 is a section on line 4-4 of Fig. 1.

As shown in Fig. 1, the humidostatic element assembly which includes a hollow body I l is suitably mounted by a flange l2 at any desired point on a duct l3 or the like, regardless of its accessibility. A perforated protecting tube It for the humidostatic element It is mounted on body II and projects through a suitable opening l'l provided for the purpose in the duct wall so that v the sensitive element is subjected. to the atmospheric conditions in the duct.

Humidostatic element l6, which may be a piece of animal membrane or any other suitable material; is connected at its outer end, by a clip II and links iii, to a screw 20 mounted in openings in a movable plate 2! and a flxedplate 22. Plate 2| is slidable on rods 23 carried by body ll, while plate 22 is fixed, as by nuts 24, on the ends of the rods. Mounted on screw 20 between the two plates is a coil spring 25, while a nut 26 on the outer end of screw 26 is adapted for manipulation to zero the instrument.

A clip 21 on the inner end of sensitive element l6 connects by links 28, 29 to a plunger 30 having an enlarged guiding and supporting flange 3| Flange 3| carries a valve or throttling portion 32 adapted to coact in the usual manner with a leak por-t member 33 to regulate the escape of air therefrom. Plunger 30 operates in a chamber 34 in body ll. Coil spring 35, interposed between flange 3| of the plunger and end wall 36 of the chamber, keeps the sensitive element l6 under constant tension, so that, as element l6 expands or contracts under the influence of varying humidity within duct I3, plunger 30 slides back and forth to vary the throttling effect of valve 32 on the leak port. Leak port 33 is carried by a ported block 31 located in a chamber 38 in body II. Block 31 is normally stationary during operation of the device but is adapted for longitudinal movement in chamber 38 to effect an adjustment of the point of initial responseof the instrument (leak port just closed) by changing the relative spacing of the leak port and valve 32. This adjustment is effected by a shiftable cam mechanically actuated from a remote point by manually operable means.

The adjusting cam above mentioned is in the form of an elongated member 39 mounted for combined longitudinal and rotary movement in a chamber 4|] in body I I. Chamber 38 opens into chamber 40 and a pair ,of internally threaded diametrically-opposed bosses ti and 42 also lead thereto. A sleeve 43 is threaded into boss 42. Cam member 39 has a central tapered or conical cam portion 44, which rests at shoulder 45 on sleeve 43, and a longitudinally-slotted depending extension 46 disposed within the sleeve so as to permit free rotation of cam member 39. upper extension 41 of cam member 39 has threaded connection with boss 4! at 48. Leak port block 31 has a pointed projection 49 engaging 'cam surface 44 of member 39. A coil spring 50 in chamber 38 acts on block 31 to constantly but yieldably maintain projection 49 and cam surface 44 in contact.

From the above it will be clear that rotation of cam member 39 will result in upward or downward movement thereof, upward movement effecting adjustment of block 31 to the left by reason of the coaction of cam surface 44 and projection 49, and downward movement effecting adjustment of block 31 to the right because of the action of spring 59 thereon. When block 31 and leak port 33 are moved to the left, the humidostat will function at a lower relative humidity, whereas, it will operate at a higher relative humidity when block 31 is moved to the right.

Mounted for rotation on shoulder 43' in sleeve 43 is a coupling member 5| having a tongue 52 (see Fig. 4) slidably projecting into slot 46' of cam member 39. Afllxed at its end to coupling member 5| and depending from sleeve 43 is a hollow, flexible drive shaft 53. Thus, extension 46 and tongue 52 form an axially extensible coupling between cammember 39 and shaft 53,

whereby rotation of the shaft rotates cam member 39 and yet permits free vertical movement of the cam member independently of the driving coupling member 5| and the drive shaft.

A removable plate 54 closes the front of chamber 40 of body ll, while a plug 55 is threaded into boss 41. A flexible leak port tube 56 is connected to leak port passage 31 in block 31, and extends upwardly in a loop and then downwardly through suitable axial passages provided therefor in plug 55, cam member 39 and coupling member 5|, and then into hollow drive shaft 53. drive shaft 53, which latter preferably is in the form of a closely coiled helical spring, are enclosed in a flexible, metal protective sheath 51.

The end of this sheath is secured in boss 43 by set screw 58. A slot 59 in body ll permits necessary movement of ,leak port tube 56 incidental to the adjustment of leak port plug 31 already described.

The above described parts comprise what may be termed the sensitive element assembly.

I The humidostat body, including the relay, the

main and branch pipe connections and the adshown in Fig. 1 as mounted on a central switchboard 60. The humidostat body includes-a housing 6| attached by screws .62 to-the switchboard and having a hinged cover 63. Attached to housing 61 is a main line pipe 64 and a branch line pipe 65, the latter extending from the device to be controlled. Main line passage 64' and branch line pipe 65', formed in housing 6|, lead to the corresponding ports of a relay 68 attached to housing 6| by screws 61. Leak port tube 56, which extends through the wall of housing 6i with protective sheath 51 and shaft 53, connects at 68 with the control chamber of relay 66. This relay may be of the type shown in the Otto patent above identified, omitting, .of course, the leak port and thermostatic bar shown in the patent drawing. Thus, in operation, the pressure in leak port tube 56 will vary in accordance with the throttling of leak port 33, which is responsive to changes of relative humidity in duct I3, and this pressure will actuate relay 66 to vary the branch line pressure. g

The remote manual operating means for flexible shaft 53 will now be described. "As shown in Figs. 1 to 3, these means include a base plate, 69 secured by screws 16 to housing 6|. Formed on this base is a perforated lug 1i and a hollow open-ended boss 12 in which a member 13, having a threaded portion 13', is mounted for rotation by knob 14 fixed on one end thereof. The oppo- Leak port tube 56 and its surrounding flexible site end of screw member 13 is enlarged at 15 and slotted at 15' to receive a tongue 11' on a coupling member 11 also adapted to rotate in boss 12-.

The end of flexible shaft 531s affixed to cou-.

pling member 11 and screw member 13 so as not to interfere with rotation of these parts. Thus it will be clear that, upon manipulation of knob 14, screw member 13 will rotate flexible shaft 53 within its sheath and, through the means described, effect movement of leak port 33 in tion of the nut without interfering with movement thereof lengthwise of screw member 13 when the latter is rotated. A pointer 85 is provided having an-extension 86 underlying horizontal portion 88 of angle member 8|. Pointer extension 88 has an opening 81 therein (see Fig. 3) through which pin 84 also projects.

A nut 88, a coil spring 88 and a washer 88 mounted on pin 84 serve to maintain pointer extension 88 in firm but yieldable contact with portion 88 of angle member 8|. Thus, when an adjustment is being made and nut 88 moves along screw 18,pin 84 in opening 81 in the pointer operates to slide the latter along angle member 8|. A graduated plate 9|, mounted on posts 92, 93 on base 88, coacts with pointer 85 to indicate the setting eflected by the adjustment.

Because of the torsional flexibility of shaft 58, there is a certain amount of backlash or loose play in the transmission between cam member 39 and operating knob 14, Assuming. knob 14 has been rotated in one direction to secure an adjustment, then when the knob is rotated reversely to change the adjustment, such rotation of the knob will take place through a certain angle without causing rotation of cam mem ber 39 and consequent adjustment of leak port 33. This initial rotation of knob 14 twists flexible shaft 53 and, only after the twisting has reached a certain degree, will cam member 88 begin its combined rotary and axial movement to adjust the leak port.

In order to compensate for this backlash or lost-motion in the transmission and thus insure that pointer 85 and graduated plate 8| always coact to indicate accurately the critical point of response for which the instrument is adjusted irrespective of the direction in which the pointer is moved, opening 81 in the pointer through which pin 84 projects is made in the form of a slightly elongated slot. pin-and-slot connection between nut 88 and pointer 85 which permits limited relativemovement between the nut and the pointer when the nut is moved during adjustment. Therefore, when knob 14 is rotated reversely to move nut 80'and pin 84 as described above, pointer 85 remains stationary, because of its frictional engagement with angle member 8|, until pin 84 engages the end slot 81 in the pointer. Thereupon the pointer and nut 88 move together as rotation of knob 14 is continued. Slot 81 is made of the proper length to provide lost-motion in the pin-and-slot connection at this point which exactly compensates for the backlash in the flexible sha '5 transmission. As a result, no matter which way knob 14 is rotated, pointer 85 moves only during actual adjusting movement of leak port block 81 by cam member 39 and, since graduatedplate 9| iscalibrated in accordance with this movement, the pointer will always accurately indicate the setting of the instrument.

This provides a slidable.

The installation, construction and operation of the device and the various practical advantages accruing therefrom will be clear from the above description. With the arrangement shown, leak port tube 56, flexible shaft 53 and protective sheath 51 may be made of considerable length if necessary and yet provide highly eflicient operating connections between the parts of the device. Y

Although a relay 88 is disclosed as a part of the device, it is clear that various advantages afforded by the described arrangement would still obtain even though the relay were omitted, and the main and branch lines and the .leak port tube directly connected so that the pressure in the branch line varies in response to variable throttling of the leak port the same as when the relay is present.

What is claimed is:

1. The combination in a device of the type described of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; adjusting means operable from a point remote from said responsive element for adjusting the critical point of response of the device, said adjusting means including a hollow rotary flexible shaft; supply and branch pipe connections located at said remote point, said connections being of the type adapted to establish in the branch line a pressure which varies in response to variable throttling of said leak port; and a fluid conductor connecting said leak port with said pipe connections and extending through said hollow shaft.

2. The combination of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; adjusting means independent of fluid pressure and operable from a point remote from said responsive element for varying the position of the leak port whereby its coaction with said throttling means is modifled; a fluid pressure relay located at said remote point, said relay being of the type adapted to establish in a'branch line a pressure which varies in response tovariable throttling of said leak port which forms part of the relay; and a fluid conductor connecting said leak port and said relay.

3. The combination of a leak port; means for variably throttling the same; a responsive eleand extending through said hollow shaft.

4. The combination of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; ad-

justing means operable from a point remote from said responsive element for varying the position of the leak port relatively to said throttling means, said adjusting means including a rotary flexible shaft; 9. fluid pressure relay located at said remote point and adapted to be controlled by variable throttling "of said leak port which forms part of the relay; a fluid conductor connecting said leak port and said relay; and a tubular casing through which both said fluid conductor and said flexible shaft extend.

leak port; valve mechanism for variably throttling the leak port, said valve mechanism being I controlled by said responsive element; a fluid pressure relay connected by a fluid conductor with said leak port and adapted to be controlled by variable throttling of said leak port which forms part of the relay; and adjusting means for varying the position of said leak port and said valve means relatively to each other, said adjusting means including 'ahollow rotary shaft through which said fluid conductor extends.

6. The combination in a device of the type described of an element operable in response to changes in an atmospheric condition; means adapted to be controlled by operation of said responsive element; means for adjusting the critical point of response of the device, said adjusting means having lost motion therein; means actuated as a result of operation of said adjusting means to indicate the critical point of re sponse for which the device is set; and means for compensating automatically for lost-motion in said adjusting means whereby to insure the accurate indication of said setting.

7. The combination in a device of the type described of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; means for adjusting the critical point of response' of the device, said means including a rotary flexible drive shaft; means actuated as a result of operation of said adjusting means to indicate the critical point of response for which the device is set; and means for compensating automatically -for lost-motion in said adjusting means caused by the torsional flexibility of said shaft, whereby accurate indication of said setting is insured.

8. The combination in a device of the type described of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; means for adjusting the critical point of response of the device, said means having lost motion therein and including a rotary member; and means actuated as a result of operation of said adjusting means to indicate the critical pointof response for which the device is set, said indicating means comprising a stationary graduated part, a coacting pointer, and means for operating said pointer by actuation of said rotary member, said operating means including a lost-motion connection to compensate automatically for lost-motion in said adjusting means and thereby insure accurate indication of said setting.

9. The combination in a device of the type described of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; means for adjusting the critical point of response of the device, said means having lost motion therein and including a rotary externally threaded member .flxed against lengthwise movement; and means latter through movement of said nut-like memher, said pin-and-slot connection permitting limited relative movement between the nut-like member and-the pointer'to compensate for lost-motion in said adjusting means and thus insure proper indication of said setting.

10. The combination in a device of the type described of a leak port; means for variably throttling the same; a responsive element for controlling said throttling means; means for adjusting the critical point of response of the device,'said means having lost motion therein and including a rotary externally threaded member sponse for which the device is set, said indicating means comprising a stationary graduated part, a movable coactlng pointer having a slotted extension, a nut-like member mounted for longitudinal movement .on said threaded member upon rotation of the latter, a stationary slotted member, a threaded stud on said nut-like member projecting through theslot in said pointer extension and also through the slot in said stationary member to prevent rotation of said nutlike member, a nut on said stud, and resilient means on said stud between the nut and said pointerextension to hold the latter in close frlctional contact with said stationary'member but permit movement of the pointer by saidstud, said stud-and-slot connection between the nutlike member and the pointer permitting sufllcient" relative movement between said member and pointer to compensate for lost-motion in said adjusting means and thereby insure accurate indication of the setting.

11. The combination in a device oithe type described of a leak port; a valve for variably throttling said leak port; movable supporting means for said leak port; movable supporting means for said valve; a responsive element operatively connected to one of said supporting means for controlling throttling of the leak port; and means for adjusting said other supporting means to vary the position of the leakport and the valve relatively to each other, said adjusting means comprising a member mountedffor longitudinal movement in said device upon operation thereof and having a. cam surface thereon engagingsaid second-mentioned supporting means to adjust described of a leak port a movable supporting,

member therefor; means for variably throttling the leak port; a responsive element for controlling said throttling means; and means for adjusting the position of said leak port relatively to said throttling means, said adjusting means comprising a longitudinally movable, rotary member having threaded connection with said device and a conical camsurface thereon engaging said leak port supporting member whereby longitudinal movement of said rotary member adjusts said supporting member, means yieldably urging face, a rotary flexible shaft for operating said rotary member, and an operative connection between said shaft and said rotary member which permits relative axial movement between the shaft and the rotary member.

- CARL A. OTTO.

said supporting member against said cam sur- ,1: 

